Radioreproducer



Decfz?, 1927. 1,653,727. y F. oBERsT RADIOREPRODUSER Filed Sept. 6L 1924 Patented Dec. 27, 1927.

Unirse" PATENT OFFICE.

FRANK 'OBI-ERSTE, 0F NEW YORK, N. Y., ASSIGNOR TO SONORA PHONOGRAPE COMPANY,

INC., A CORPORATION OF NEW YORK. i

RADIOREPRODUCER.

Application tiled September The present invention relates generally to the free operation of a diaphragm by im pulses at audio frequency for reproduction ot sound and more particularly to the employment et' means'which will improve the acoustic and resonant qualities of the reproduction. ln order that a diaphiagm mayfreely'vibrate thus giving best results, it is necessary that the air pressure on each race must at alltimes be equaliized. In the present state of the art radio reproducers are so constructed as to have one side of the diaphragm open to'atinospheric pressure, to allow tree egress of the sound, While the other side containing the actuating elements,A is enclosed in a substantially air and sound proof housing to protect these eleu'ients. Thus, in vibrating, the diaphragm is subjected to atmospheric pressure on the one side, and on the other, the air trapped in this protective housing is subjected to alternate compression and expansion. rlhis latter acts as an air-brake in restraining` the free vibrations of the diaphragm, thus pro# ducing a somewhat inutlled sound, and greatly detraeting from its efficiency.

One ot the objects of my invention is to provide a radio reproducer with means so constructed, and arranged as to improve the lacoustic and resonant qualities of the reproduction.

A further object of myv intention `is to provide an improved radio construction Which has no trapped air, and which, at all times, subjects both faces ot' the `adio repro# ducer diaphragmto equal air pressure. so that its vibrations are unrestrained, and the sound is entirely unrnull'led, and the quality and volume ot the reproduced sound will be greatly improved.

A further object of my invention due to equalizing the air pressure, is that the operating parts ot the radio reproducer expend all their energy in vibrating the dia.- phragm, and none in useless expansion and contraction et idle air, thus promoting much `higher etiicieney` lengthening the life oiI the parts, and with less likelihood of their getting out of order.

`With this and other objects in view, to be more tully set forth hereinafter, the invention consists in the novel construction.v combination ot elements, and arrangement ot parts, which will be exemplified in the op- 'sott 6, 1924. Serial N0.`736,234.

eration and construction herein described in the following specification and illustrated iu the awompanying drawings.

The. inventive idea involved is capable or receiving a variety of mechanical expressions, one of which, for the purpose of illustration, is shown in the accompanying4 drawings.

The invention Will first be described in connection with the accompanying draw-v ings, wherein similar reference characters 05 are used to designate corresponding parts throughout the several views, and then more specifically defined and indicatedin-the appended claims. 'l'

Attention is directed to the drawings i'n 70 which:n A

Figure 1 is ay central sectional elevation, of ay radio reproducer with my improved housing mounted thereon.

Figure 2 is a rear elevation of a radio re- 75 producer with my improved housing mounted thereon, and,

Figure 3 is a. detail view of 'my improved radio reproducer housing showing the protective screen, l j

For purpose et illustration l show 'my invention applied to the usual electro-,magnetic radio reproducer, which has face plate 1 with central opening 2 for the ready exit of the sound set up by diaphragm 3 clamped 85 between annular rings 4 by means of screws 5 passing through face plate 1, annular meinber (i and ring 7 as shoivn in Fig. 1.

The diaphragm 3 is actuated in the usual manner by electric impulses passing through 90 coils S surrounding a portion of the magnets 9 which oscillate armature 10. These oscillations are transferred to the diaphragm by means of link 11. Enclosing these operating parts, and secured to ring 7 by means 95 of screws 14 through holes 15 (Fig. 3) in flange 1G is my improved housing 12 having pertorations 13.

lu the lower part ot housing 12 is provided an opening 17 for the admission of 100 wires 1S) to carry the electric pulsations to the coil S. These Wires are protected inl passing through this housing opening `by gasket 18. .lt is important that pertorations 13 105 should be as tree from obstructions as possible, hou'ever it is necessary to protect the operating parts from the sitting in of dust or dirtlor the introduction of foreign matter,

therefore I 'provide inside the hous and covering these` perforations, a ely mesh screen 2O held 1n place firmly by a.n4 nular wire ring 21 soldered to' the housing 1231s at 22 (see Fig. 3). j f

- As will be readily seen this improved housing provides a construction which at all times allows the alternate compression and expansion of air, caused by the vibration ot thedipahragm, to have free and continuous access to the outside `atmosphere both in back as Well as in front of the diaphragm.

` resonant proved.

Thus there is no opportunity for the air to be trapped and the diaphragmsaction orA movement is entirely free from dampening or muiiiing, and the sound roduced is ot' highly efficient volume and t e acoustic and qualities vof the sound greatly imthe invention can be carried out in other aol ent, is zways without departing from the spirit of my invention, and, l therefore, I claim broadly the right to employ all e uivalent nstrumentalities coming within t e1 scope of the appended claims, and by means of which objects of my invention are attained, and new results accomplished, as herein set forth, as it is obvious that the particular embodiments herein shown and described are only some of many that can be employed to attain these objects and accomplish these results.

Having now described my invention, what I claim and desire to secureby Letters Pat- 1. In a telephone receiver, a diaphragm chamber comprising an annular body member having a peripheral fiange, an annular Lesage? face plate and an annular baclr plate both seated against said body member within said iiange to form a cylindricalv diaphragm chamber, means to sup rt telephone magnetic elements from saiback late and beyond said chamber and a cylin rical housing covering said magnetic elements and secure to said diaphragm chamber.

V2. In a telephone receiver, a diaphragmV ,chamber comprism an annular body member having a perip eral ange, an annular faceplate and an annular back plate both seated against said body member within said flange to form a cylindrical diaphragm,

chamber, means to support telephone magnetic elements from said back plate and beyond said chamber and a cylindrical aper tured housing covering said ma netic elements and secured to said iaphragm chamber. v

3. In a telephone receiver, a diaphragm chamber, Atelephone magnetic elements sup-l ported to the rear ofl said chamber,` a

5. In a telephone receiver, a diaphragm L chamber, telephone magnetic elements supported from the walls of and in the rear of said chamber, a cylindrical cap of thin sheet material enclosing said magnetic elements said cap being supported from the walls of said chamber and having a flat rear wall providedwith va rowT of relatively large area apertures adjacent the edge of said wall.

This specification signed and witnessed this 20th day of August, 1924.

FRANK OBERST. 

